EP 682 437 is known which relates to an automatic sound volume control device for a telephone. The sound volume is automatically controlled as a function of the ambient noise so as to deliver the sound level that is adapted best to the listening conditions. The telephone detects the presence of words pronounced by the user so as to measure the noise outside these periods of words. The corrections are made with the aid of amplifier means which apply a gain variation law covering the range of the noise level. The apparatus thus described unburdens the user of any work he has to carry out during his telephone communications. This may be insufficient in certain conditions of use. Particularly, a mobile telephone may be used under conditions of diverse and variable noise to which may be added more or less good-quality links with the called party and a dependence on the level at which the called party's voice is received, which level causes a signal of higher or lower amplitude to be received, so that the restored sound signal may become hard to hear by a user. In fact, the intensity of the called party's voice may vary with his/her position relative to the microphone, or with the strength of his/her voice. On the other hand, the auditive faculties of the telephone user vary from one user to the next. All these reasons make that it is desirable to permit the user to react at a sound level that is restored in accordance with his preferences.